Rebecca Adlington, the two-time Olympic champion and most successful British swimmer in a century, has retired from the sport at the age of 23 to focus on establishing swimming as a life skill in the UK.

The Mansfield-born freestyle swimmer was the first British woman to win a gold medal in the pool in 48 years when she won the 400m in Beijing in 2008, and became the first Briton to win two swimming golds at an Olympiad in 100 years when she broke the 800m world record, a mark that still stands today.

"I hate the word retire," said Adlington, who also claimed gold medals at the European and World Championships during her career. "I love swimming, but as a competitive element and elite athlete, I won't compete any more.

"I have achieved everything I wanted to. Some people want to milk it all they can. I've always said I wanted to finish on a high, despite my love of the sport.

"I had to look at things, take a break and see how I felt when I came back [after London 2012]. It didn't feel the same getting back into training and it felt like time.

"I certainly can't compete with [younger swimmers]," added Adlington. "I can't do the same level of work, I need far more time for recovery. It's time. Beijing changed my entire life, everyone wanted to learn about me. It was the best moment of my entire career. I am so glad my world record still stands."

Adlington, who also won bronze medals in the women's 400m and 800m freestyle events at the London Olympics 2012, departs following the appointment of her coach and mentor Bill Furniss as British Swimming's new head coach.

"Now I've not got Bill with me, I feel a little bit lost. The medals - they are not just mine - they are my family's, Bill's. I think he is going to do such a brilliant job."

She had already ruled out competing at the Rio Olympics in 2016, feeling that as a 27-year-old she would be too old to be competitive, but was expected to defend her Commonwealth Games titles - also in the 400m and 800m - in Glasgow in 2014.

"I will always be swimming, even when I'm 90 years old," Adlington added, as she prepares to focus on her campaigning work.

"I'm very proud of what I have achieved so far but my journey is not finished yet.

"My vision is that every child in Britain will be able to swim 25m by the time they leave primary school. Being able to swim is such a wonderful life skill, and I see this as my greatest challenge in swimming."

British Olympic Association chairman Lord Sebastian Coe led the tributes to Adlington, describing her as a "national treasure.

"Becky Adlington's unforgettable success in Beijing inspired a generation to get in the pool and swim," Lord Coe said.

"Becky's vision for the future of grass-roots swimming in this country will create a wonderful legacy for one of our greatest Olympians. I've no doubt this vision will be pursued with the same drive, determination and dedication as Becky consistently displayed in the pool."

"Becky and I have become great friends over the years since the Beijing Olympics," added Sir Chris Hoy, Britian's most decorated Olympian. "The sheer scale of what she has achieved - not only for herself but also for swimming in this country - is amazing. She's been the standard-bearer for her sport for a long time now and I expect that to be the case for many years to come."

American swimmer Michael Phelps, the most decorated Olympian of all time, wished Adlington luck in her future endeavours.

"Our paths have crossed many times over the years. Her accomplishments speak for themselves," Phelps said. "She's been a great representative for British swimming and the sport overall. I congratulate her on a fantastic career."